package com.anytron.utils;

import java.io.InputStream;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;

public class LinuxShell {

	private Session session;

	/**
	 * 远程登录
	 *
	 * @param host     主机ip
	 * @param port     端口号，默认22
	 * @param user     主机登录用户名
	 * @param password 主机登录密码
	 * @return
	 * @throws JSchException
	 */
	public void login(String host, int port, String user, String password) {
		try {
			if (port == 0) {
				port = 22;
			}
			JSch jsch = new JSch();
			session = jsch.getSession(user, host, port);
			session.setPassword(password);
			// 设置第一次登陆的时候提示，可选值:(ask | yes | no)
			session.setConfig("StrictHostKeyChecking", "no");
			// 连接超时
			session.connect(1000 * 10);
		} catch (JSchException e) {
			System.out.println("登录时发生错误！");
			e.printStackTrace();
		}
	}

	/**
	 * 关闭连接
	 */
	public void close() {
		if (session.isConnected())
			session.disconnect();
	}

	/**
	 * 执行命令
	 *
	 * @param command
	 * @return
	 * @throws Exception
	 */
	public String executeShell(String command) throws Exception {
		byte[] tmp = new byte[1024];
		StringBuffer resultBuffer = new StringBuffer(); // 命令返回的结果
		Channel channel = session.openChannel("exec");
		ChannelExec exec = (ChannelExec) channel;
		// 返回结果流（命令执行错误的信息通过getErrStream获取）
		InputStream stdStream = exec.getInputStream();
		exec.setCommand(command);
		exec.connect();

		try {
			// 开始获得SSH命令的结果
			while (true) {
				while (stdStream.available() > 0) {
					int i = stdStream.read(tmp, 0, 1024);
					if (i < 0)
						break;
					resultBuffer.append(new String(tmp, 0, i));
				}
				if (exec.isClosed()) {
					break;
				}
				try {
					Thread.sleep(200);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		} finally {
			// 关闭连接
			channel.disconnect();
		}
		return resultBuffer.toString();
	}
}
